Continued characterization and attempted solubilization of the guinea pig basophil granule enzymes and other granule proteins. Characterization of the mucopolysaccharides synthesized by guinea pig basophilic leukocytes. Localization of plasminogen activator activity found in highly purified basophil preparations. Studies aimed at elucidating the nature of basophil-tumor cell interactions in vitro, with particular emphasis on determining whether basophils serve as a tumor-killing cell.